The present invention relates generally to improvements in electrical cord and cable fittings and it relates particularly to an improved device for hermetically sealing and anchoring and grounding an armored cable to a wall or partition through which the cable passes to relieve the strain on the leading end of the cable.
It is a common practice to pass a flexible plastic sheathed metal or armored or jacketed electrical cord or cable through a wall or partition and connect the cable conductors to one or more terminals and ground the metal jacket. The wall or partition may be a metal wall of a junction, switch or terminal box or the like and it is important that any strain on the cable be prevented from being transmitted to the terminals to which the cable conductors are connected to thereby maintain a reliable connection to the terminals and to ground the metal jacket. It is additionally desirable that the cable be hermetically sealed to the wall through which it passes to prevent the exposure of the conductors and terminals to moisture and corrosive ambient atmospheres. Many devices have been available and heretofor proposed for anchoring and sealing a cable to a wall of a junction terminal or switch box or the like but these have possessed numerous drawbacks and disadvantages. They have been complex and often unreliable devices, of little versatility and adaptability, expensive and have otherwise left much to be desired.
A cable fitting of the subject type is disclosed in U.S. Pat. No. 4,835,342, dated May 30, 1989, and, while the disclosed fitting is highly superior for use with electrical cord or cable of the non-armored type, its use with metal armored or jacketed cable, particularly where the jacket is plastic sheathed, possesses an important drawback in that the metal jacket is ungrounded and its hermetic sealing presents many problems.